PROSPECTIVE TRIAL OF CONSERVATIVE SURGERY AND SELECTIVE USE OF RADIOTHERAPY FOR T1 EXTREMITY AND TRUNK SOFT TISSUE SARCOMAS (STS)

Respondek P, Pollack A, Feig B, Yasko A, Hunt K, Weber K, Lin P, Griffin J, Patel S, Benjamin R, Zagars G, Pollock R, Pisters P (The Sarcoma Center, The University of Texas M D Anderson Cancer Center, Houston, TX 77030).

Purpose: Recent retrospective reports have suggested that some patients with T1 primary STS can be treated by surgery alone. To better define which patients can be treated by surgery alone, we initiated a prospective trial evaluating conservative surgery with selective use of postoperative external-beam radiotherapy for patients with T1 extremity and trunk STS.

Methods: Patients with T1 primary extremity and trunk STS were treated with conservative, limb-sparing surgery and microscopic assessment of surgical margins. The treatment approach was based on the presence or absence of measurable disease at presentation and the final microscopic status of surgical margins. Patients presenting with primary STS in situ underwent conservative surgery with microscopic assessment of margins. Patients referred following pre-referral excision with microscopically equivocal or frankly positive margins underwent re-excision of the scar and tumor bed with microscopic reassessment of margins. Patients referred following pre-referral excision with unequivocally negative margins underwent observation only. Postoperative external-beam radiotherapy was employed selectively for all patients with microscopically positive final surgical margins. Patients with microscopically negative final margins did not receive radiotherapy.

Results: Forty-six patients have been entered on this protocol since February 1, 1996. STS were located in the lower extremity (n=16), upper extremity (n=9), and trunk (n=21). Twenty-seven patients (59%) had high-grade lesions; 30 patients (65%) had superficial lesions. Thirty-eight patients presented following pre-referral excision with equivocal or positive margins and were treated with re-excision and microscopic reassessment of margins. Seven patients with measurable disease were treated by one-stage surgical resection and margin assessment. One patient presented after pre-referral excision with microscopically negative margins. Five patients with microscopically positive final surgical margins were treated with postoperative radiotherapy. The median follow-up is 12 months (range, 3-35 months). Local recurrences have been observed in 2 patients (4%), 1 of whom received radiotherapy; these patients had lesions located in the groin and the forearm, sites where wide local excision with satisfactory gross margins can be difficult. Regional (nodal) and distant recurrences have been observed in 2 patients each.

Conclusion: With relatively short-term follow-up, the local recurrence rates among patients treated by surgery alone (1/41, 2%) do not appear prohibitively high. Additional patients and longer follow-up will be required to determine which, if any, subsets of patients with T1 STS can be treated by surgery alone.